Coral pinnicle with shark and conger eel

Clay wall in place and silicone applied


Clay wall removed. Silicone trimmed ready for plaster mother mould (different views)






Mould opened up

 

Which modeling clay are you using? What dye for the silicon rubber to get different colors? Whats the white outer part of the mold? Is that the moldable plastic stuff or plaster?

 

For the sculpture its chavant soft or medium cant remember which as i have thrown away the packaging. If you mean for building parting line bases and walls its just a simple water based clay, the stuff they use for pottery. I just add a few drops of the liquid food colouring as the dye for the silicone. The white outer mould is just simple plaster the cheapest i could find. I did buy some plastic mesh so strengthen the plaster but didnt use it as yet.
Hows things with you Zapins? Are you working on anything at the moment?

 

Gotcha. Does the plaster and mesh hold up well long term?

Things are going well all things considered. I've been working mostly in my new garage shop on random projects. Basically getting full use of it since I haven't had access to it over the last 10 years or so.

In terms of casting projects I've got the chicken sculpture on hold and I started doing a new iron fire place grate replacement. I have the wax done but I need to buy a new crucible for iron before I cast it. But that's also been on hold lately since I've had to support my parents after they lost their house due to covid job loss. So my cash has been somewhat more limited than it has been before.

 

yes the plaster is stable. I still have all my old moulds. Obviously they smash if dropped. I havent used the mesh yet. If i did anything the size of your octopus then i would use it. Alternatively banage wouldbe good too. Maybe better as more flexible to apply. Just like plaster casts for broken bones. Those casts are quite strong and could survive being dropped too. The bandage also means you could make them thinner too.
Is that a special type of cruicible youre getting for the iron or just a bigger one?
Sorry to hear about your parents loosing their house. Will they be able to get their jobs back when things return to normal?

 

I'm still a bit unsure of the type of crucible I need. I heard the silicon carbide aren't good for iron so maybe a clay graphite?

My mom got another local job. My dad hasn't gotten one yet its been since the covid mess started. His job is pretty specialized and the oil industry isn't making a lot of new projects so he hasn't gotten another one yet.

 

Yeah surprisingly I don't see too many broken bones. They all get filtered out and treated by the ED or referred to ortho before making it to the hospital floors. I've done a couple here and there but definitely don't see many. The ED has all the fun.

 

Im suprised Z that it never crossed your mind to use pop and bandages over fibre glass with your medical background. One to try with the chicken maybe

 

I considered it but felt it might be too weak compared with fiberglass. But now that you mention it casts are pretty sturdy and seem to hold up for ages so it would probably work fine like you say.

 

about half way through the mold making. At least all the large ones are done

 

Very nice. Are you getting any bubbles in the tiny details?

 

not that i can see, there are some defects where the silicone didnt flow into some deep areas such as in the eels mouth. I will initially put the clay original back in the mould and see if i can drop in a bit of silicone in. If it doesnt stick to the existing silicone i may remake the mould.

these are just test casts using old wax (its got alot of contaminants in it) to see how the molds perform and to see if i can remove the waxes easily. I have new wax that I will use when I come to do the proper casts.
there were some bubbles on the shark cast i did a few weeks ago. I think this was due to the wax being too hot and gasses formed around the particles of contaminents just like co2 bubbles do in a glass of fizzy drink. I think the new wax will stop this

 

On to the more complex pieces now. Havent showed pics of the whole process as its the same as previous moulds.
This type I decided to cut up into smaller pieces and make a simple two part mould rather than making a complex multipart mould of such a small piece.
I will make the piece each time from the cast wax components.

 

The rest of the moulds finished. All moulds have now been completed (20 in total). Some of the smaller pieces of coral I placed next to each other and combined into one mould to save time and materials. You can tell these ones as they have multiple openings for pouring the wax.

Next stage producing the wax copies and constructing the complete sculpture. Then comes the tricky bit of designing the sprueing system too take into account that some parts will be hollow and relatively thin walled and other parts will be solid and much thicker. I predict a number of failed casts when I start pouring metal

 

cast 3 of everything so i can do a bit of experimenting with the sprueing. Some of the pieces will be solid and up to 2cm thick others will be hollow and less than 10mm thick.

Now to construct the full sculpture as it will look.

 

Such a lot of work!!

Very clean copies. What wax are you using?

Do you reclaim it after burn out?

 

Its just called lost wax wax.
https://www.specialplasters.co.uk/waxes/lost-wax.html
Its very hard so holds detail well. But one little knock and it breaks easily, very brittle under normal temps.
I have been reclaiming it in the past. The stuff I used here is new so not reclaimed yet.
It took 2 days to get to learn the moulds characteristics and cast all the pieces you can see. There were many fails until I learned how best to pour each mould.
There are some imperfections, but that is due to poor mould making. I was rushing towards the end and some of the silicone has bubbles in it on some of the moulds that I didnt originally notice, and so will require some touching up prior to ceramic shell application.
I still have the clay original pieces so may redo some of the moulds at some point.

 

I used slightly under 3kg of silicone to do all the moulds
https://www.ebay.co.uk/itm/303343218572?var=602447742301
Came to about £55 so quite cost effective

 

Found some time to put the wax bits together to make the finished piece.
Any suggestions for sprueing this?
Also anyone know how to rotate the images? The ones on my PC are the correct way around